1. Field of the Invention
The present invention relates to a water filtering device for a humidifier and, more particularly, to a water filtering device capable of inducing ionic bonding between water and an ion exchange resin for a sufficient time to increase filtration performance of a water filter.
2. Description of the Related Art
As is well known, tap water used in a humidifier mainly contains mineral components such as magnesium (Mg2+), calcium (Ca2+), and so on in an ionized state.
Such mineral components (mainly Ca2+ and Mg2+) may be extracted from tap water in the form of scales sticking to the heater or inner pipes when the tap water is heated. When the stuck mineral scales are left as they are, the heater may overheat or the pipes may clog and cause malfunction of the humidifier. Therefore, the scales of mineral components should be previously removed.
However, since the scales of the mineral components are hard as stone and securely stuck to the humidifier, it is very difficult to remove them.
In addition, the scales of mineral components may be formed of positive ion carbonate, hydroxide or oxide of Ca, Mg, Na, K, Fe, Cu, and so on, and are mainly formed of a carbonate or hydroxide of Ca and Mg, specifically, calcium carbonate, magnesium carbonate, and magnesium hydroxide.
In order to prevent the scales of mineral components from forming, Korean Patent Application No. 2000-7014218 (hereinafter, referred to as conventional art 1) and Korean Patent Registration No. 462227 (hereinafter, referred to as conventional art 2) disclose technology of filling a water filter with an ion exchange resin for a humidifier to adsorb the mineral components through ionic bonding between water and the ion exchange resin, thereby removing the mineral components.
In conventional art 1 and 2, the water filter filled with the ion exchange resin is installed in a storage tank, and water in the storage tank can always be replaced by an equal volume of air, so that the inside of the storage tank always stays at atmospheric pressure enabling the water to be smoothly supplied to a heating device.
However, the water filter of conventional art 1 has a structure in which an inner cylinder 2 and a partitioned cylinder 3 in a case 1 are incorporated in one body with the case 1 through injection molding to provide an air flow path A, as shown in FIG. 1. As a result, an inner space B provided between the inner cylinder 2 and the partitioned cylinder 3 must have a fixed spatial volume, in the step of manufacturing the water filter.
Specifically, while the water entering the water filter should be discharged through the outer space C and the inner space B of the case 1 without mineral components, since the inner space B of conventional art 1 is too small due to the inner cylinder 2, the amount of ion exchange resin that it can accommodate is limited. Therefore, ionic bonding between the water and the ion exchange resin is performed for a short time, and adsorption and removal of the mineral components in the water cannot be perfectly performed. As a result, the scales of the mineral components are extracted by heating the heater, and the extracted scales of the mineral components are stuck to the heater or pipes, causing the heater to overheat or the pipes to clog or malfunction.
In addition, in conventional art 2, in order to more readily exchange the ion exchange resin than in conventional art 1, a case 1 and an upper cap 4 are threadedly engaged with each other. However, since an inner cylinder 2 and a partitioned cylinder 3 in the case 1 are also incorporated into one body with the case 1 through injection molding, the same problems as in conventional art 1 are generated.